JP2019169352A - Nickel hydrogen battery and manufacturing method of power storage module - Google Patents

Abstract

To provide a nickel hydrogen battery and a manufacturing method of a power storage module, capable of achieving high output.SOLUTION: A nickel hydrogen battery 12 includes a lamination body 30 in which a bipolar electrode 32 formed by an electrode board 34 in which an electrode 36 is formed in one surface, and a negative electrode 38 is formed in the other surface is laminated in a Z direction through a separator 40. The nickel hydrogen battery 12 comprises: a frame body 50 housing the lamination body 30; and a pressure adjustment valve 60 connected to an opening 50a that communicates to an inner space V surrounded by the frame body 50. The inner space V includes a first region V1 in which an electrolyte containing potassium hydroxide exists and a second region V2 in which no electrolyte exists, and an atmosphere of the second region V2 is lower than an atmospheric-pressure, and higher than a saturation vapor pressure of the electrolyte.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a nickel metal hydride battery and a power storage module.

  A power storage module (bipolar battery) including a bipolar electrode in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the other surface is known (see Patent Document 1). In this power storage module, an electrolytic solution is sealed in a partial region of the internal space formed by the separator, the current collector, and the seal member. Bipolar electrodes are laminated via an electrolyte layer made of a separator impregnated with an electrolytic solution. The power storage module is provided with a tube that penetrates the seal portion. One end of the tube faces the internal space, and the other end faces the external space of the battery. When the pressure in the internal space increases while using the power storage module, this tube functions as a pressure regulating valve.

JP 2010-287451 A

  Since the electrolytic solution exists in the internal space of the power storage module as described above, gas may be generated from the electrolytic solution during charging and discharging. For this reason, the remaining space in which the electrolyte does not exist is provided in the internal space so that the pressure regulating valve does not act immediately even when gas is generated. However, when the output of the power storage module increases, a large amount of gas may be generated instantaneously, which may cause the pressure regulating valve to act and cause the electrolyte to leak out. Therefore, there has been a limit to increasing the output of the power storage module.

  An object of this invention is to provide the manufacturing method of the nickel hydride battery and electrical storage module which can achieve high output.

  A nickel metal hydride battery according to the present invention has a laminate in which a bipolar electrode composed of an electrode plate having a positive electrode formed on one surface and a negative electrode formed on the other surface is stacked in a first direction via a separator. A nickel-metal hydride battery, comprising: a container that houses the laminated body; and a pressure regulating valve that is connected to an opening that communicates with the internal space surrounded by the container, and the internal space includes an electrolytic solution containing potassium hydroxide. And a second region where no electrolytic solution exists, and the atmospheric pressure in the second region is lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution.

  In the nickel-metal hydride battery having this configuration, the atmospheric pressure of the second region (remaining space in which no electrolyte solution exists) in the internal space is lower than the atmospheric pressure. For this reason, the pressure rise when the gas is filled in the second region is moderated. In other words, the second region, which is lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolyte, can accept a larger amount of gas before reaching a certain pressure than the second region in the atmospheric pressure state. it can. As a result, even if a large amount of gas is generated instantaneously, the time until the pressure regulating valve acts increases, so that the output of the nickel-metal hydride battery can be increased. The pressure regulating valve here includes both a configuration that closes again when the pressure in the internal space is released, and a configuration that does not return to the closed state even if the pressure in the internal space is released. .

  In the nickel metal hydride battery according to the present invention, the volume of the second region may be greater than 0 mL and 10 mL or less. Since the internal space of the nickel metal hydride battery is a very narrow space in which the volume of the second region is larger than 0 mL and not more than 10 mL, the pressure is likely to rise. Even with such a configuration, it is possible to increase the output of the nickel-metal hydride battery.

  The pressure regulating valve may be opened when the pressure in the internal space is in the range of 0.5 MPa to 1.2 MPa.

  In the nickel metal hydride battery according to the present invention, the atmospheric pressure in the second region may be 50 kPa or less. As a result, the output of the nickel-metal hydride battery can be increased more efficiently.

  In the nickel metal hydride battery according to the present invention, the container is a frame body that holds the periphery of the electrode plate and covers the side surface orthogonal to the first direction in the laminate, and the pressure regulating valve includes the electrode and the frame that are adjacent to each other. You may connect to the opening connected to each of the some internal space enclosed by the body. Thereby, even if it is a case where a pressure control valve is provided in the opening provided in the frame which covers the side surface orthogonal to the 1st direction in a laminated body, high output can be achieved.

  In the method for manufacturing an electricity storage module according to the present invention, a laminated body in which an electrode made of an electrode plate on which at least one of a positive electrode and a negative electrode is formed is laminated in a first direction via a separator, and a container that houses the laminated body, A pressure regulating valve connected to an opening communicating with the internal space surrounded by the container, wherein the pressure in the internal space is lower than the pressure in the external space of the container, and the internal space An electrolyte solution injection step of injecting an electrolyte solution into the internal space due to a pressure difference between the external space and an adjustment space connecting step of connecting a pressure adjustment valve to the opening of the internal space into which the electrolyte solution has been injected. The injection step adjusts the amount of electrolyte to be injected so that a region where the electrolyte does not exist is formed in the internal space, and the adjustment valve connection step is lower than the atmospheric pressure and lower than the saturated vapor pressure of the electrolyte. High pressure Pressure regulating valve is connected to an opening in the boundary under.

  In this power storage module manufacturing method, the pressure regulating valve is connected to the opening of the laminate into which the electrolytic solution is injected in an environment lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. The pressure in the internal space after connection can be made lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolyte. For this reason, the pressure rise when the gas is filled in the second region is moderated. In other words, the second region, which is lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolyte, can accept a larger amount of gas before reaching a certain pressure than the second region in the atmospheric pressure state. it can. As a result, even when a large amount of gas is generated instantaneously, the time until the pressure regulating valve acts increases, so that the output of the power storage module can be increased.

  In this method of manufacturing a power storage module, the electrode is a bipolar electrode in which a positive electrode is formed on one surface of an electrode plate and a negative electrode is formed on the other surface, the power storage module is a nickel metal hydride battery, May contain potassium hydroxide. The nickel-metal hydride battery produced by such a production method can also increase the output of the nickel-metal hydride battery.

  The container used in the method for manufacturing the power storage module is a frame body that holds the periphery of the electrode plate and covers a side surface orthogonal to the first direction in the laminated body. A pressure regulating valve may be connected to an opening communicating with each of the plurality of internal spaces surrounded by the frame. Thereby, even if it is a case where a pressure control valve is provided in the opening provided in the frame which covers the side surface orthogonal to the 1st direction in a laminated body, high output can be achieved.

  In the adjustment valve connection step of the method for manufacturing the electricity storage module, the pressure adjustment valve may be connected to the opening in a pressure environment of 50 kPa or less and higher than the saturated vapor pressure of the electrolyte. As a result, the output of the power storage module can be increased more efficiently.

  In the adjustment valve connection step of the method for manufacturing the power storage module, the amount of the electrolyte to be injected may be adjusted so that the volume of the region where the electrolyte does not exist in the internal space is greater than 0 mL and equal to or less than 10 mL. Since the internal space of this power storage module is a very narrow space in which the volume of the second region is larger than 0 mL and not larger than 10 mL, the pressure is likely to rise. Even when a power storage module having such a configuration is manufactured, it is possible to increase the output of the power storage module.

  According to the present invention, high output can be achieved.

It is a schematic sectional drawing which shows an electrical storage apparatus provided with the electrical storage module which concerns on one Embodiment. It is a schematic sectional drawing which shows one Embodiment of the electrical storage module shown by FIG. It is a perspective view which shows the electrical storage module shown by FIG. It is a disassembled perspective view of the pressure control valve connected to the side surface of a laminated body. (A) is a figure which shows the side surface by the side of the base member of a case member, (B) is a figure which shows the side surface by the side of the cover member of a case member. It is a schematic sectional drawing which shows the structure of a pressure regulating valve. It is a flowchart which shows an example of manufacture of the electrical storage module of FIG.

  Hereinafter, an embodiment will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and redundant descriptions are omitted. 1 to 6 show an XYZ orthogonal coordinate system.

  First, the structure of the electrical storage apparatus 10 provided with the nickel metal hydride battery 12 which concerns on one Embodiment is demonstrated. The power storage device 10 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles.

  The plurality of nickel metal hydride batteries 12 can be stacked via a conductive plate 14 such as a metal plate. When viewed from the stacking direction D1 (Z direction), the nickel metal hydride battery 12 and the conductive plate 14 have, for example, a rectangular shape. Details of each nickel metal hydride battery 12 will be described later. The conductive plates 14 are also arranged outside the nickel metal hydride batteries 12 located at both ends in the stacking direction D1 of the nickel metal hydride batteries 12, respectively. The conductive plate 14 is electrically connected to the adjacent nickel metal hydride battery 12. As a result, the plurality of nickel metal hydride batteries 12 are connected in series in the stacking direction D1. In the stacking direction D1, a terminal member 24 is connected to the conductive plate 14 located at one end, and a terminal member 26 is connected to the conductive plate 14 located at the other end. The terminal member 24 may be integral with the conductive plate 14 to be connected. The terminal member 26 may be integrated with the conductive plate 14 to be connected. The terminal member 24 and the terminal member 26 are extended in the direction (X direction) crossing the lamination direction D1. The terminal member 24 and the terminal member 26 can charge and discharge the power storage device 10.

  The conductive plate 14 can also function as a heat radiating plate for releasing heat generated in the nickel metal hydride battery 12. When a refrigerant such as air passes through the plurality of gaps 14a provided inside the conductive plate 14, heat from the nickel metal hydride battery 12 can be efficiently released to the outside. Each gap 14a extends, for example, in a direction (Y direction) intersecting the stacking direction D1. The conductive plate 14 is smaller than the nickel metal hydride battery 12 as viewed from the stacking direction D1, but may be the same as or larger than the nickel metal hydride battery 12.

  The power storage device 10 may include a restraining member 16 that restrains the alternately stacked nickel-metal hydride batteries 12 and the conductive plates 14 in the stacking direction D1. The restraining member 16 includes a pair of restraining plates 16A and 16B and a connecting member (bolt 18 and nut 20) for joining the restraining plates 16A and 16B to each other. An insulating film 22 such as a resin film is disposed between the restraining plates 16A and 16B and the conductive plate. Each restraint plate 16A, 16B is comprised, for example with metals, such as iron. When viewed from the stacking direction D1, each of the restraining plates 16A and 16B and the insulating film 22 has, for example, a rectangular shape. The insulating film 22 is larger than the conductive plate 14, and the restraining plates 16 </ b> A and 16 </ b> B are larger than the nickel metal hydride battery 12. As viewed from the stacking direction D <b> 1, an insertion hole H <b> 1 through which the shaft portion of the bolt 18 is inserted is provided on the edge portion of the restraining plate 16 </ b> A at a position outside the nickel metal hydride battery 12. Similarly, an insertion hole H2 through which the shaft portion of the bolt 18 is inserted is provided at a position on the outer side of the nickel metal hydride battery 12 at the edge portion of the restraining plate 16B when viewed from the stacking direction D1. When each restraint plate 16A, 16B has a rectangular shape when viewed from the stacking direction D1, the insertion hole H1 and the insertion hole H2 are located at the corners of the restraint plates 16A, 16B.

  One restraint plate 16 </ b> A is abutted against the conductive plate 14 connected to the terminal member 26 via the insulating film 22, and the other restraint plate 16 </ b> B attaches the insulating film 22 to the conductive plate 14 connected to the terminal member 24. Has been hit through. For example, the bolt 18 is passed through the insertion hole H1 from one restraint plate 16A side to the other restraint plate 16B side, and a nut 20 is screwed to the tip of the bolt 18 protruding from the other restraint plate 16B. Yes. As a result, the insulating film 22, the conductive plate 14, and the nickel metal hydride battery 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction D1.

  2 is a schematic cross-sectional view showing a nickel metal hydride battery constituting the power storage device of FIG. The nickel metal hydride battery 12 shown in the figure includes a laminate 30 in which a plurality of bipolar electrodes (electrodes) 32 are laminated. The laminated body 30 has, for example, a rectangular shape when viewed from the lamination direction D1 of the bipolar electrode 32. A separator 40 may be disposed between the adjacent bipolar electrodes 32. The bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on one surface of the electrode plate 34, and a negative electrode 38 provided on the other surface of the electrode plate 34. In the stacked body 30, the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one bipolar electrode 32 adjacent in the stacking direction D 1 across the separator 40, and the negative electrode 38 of one bipolar electrode 32 is connected to the separator 40. Is opposed to the positive electrode 36 of the other bipolar electrode 32 adjacent in the stacking direction D1. In the stacking direction D1, an electrode plate 34 (negative electrode termination electrode) having a negative electrode 38 disposed on the inner surface is disposed at one end of the stacked body 30, and a positive electrode 36 is disposed on the inner surface at the other end of the stacked body 30. The disposed electrode plate 34 (positive terminal electrode) is disposed. The negative electrode 38 of the negative electrode-side termination electrode faces the positive electrode 36 of the uppermost bipolar electrode 32 with the separator 40 interposed therebetween. The positive electrode 36 of the positive terminal electrode is opposed to the negative electrode 38 of the lowermost bipolar electrode 32 with the separator 40 interposed therebetween. The electrode plates 34 of these termination electrodes are connected to the adjacent conductive plates 14 (see FIG. 1).

  The nickel metal hydride battery 12 includes a frame body 50 that holds the edge portion 34a of the electrode plate 34 on the side surface 30a of the stacked body 30 extending in the stacking direction D1. The side surface 30a of the multilayer body 30 includes an end surface that connects one surface of the electrode plate 34 to the other surface. The frame body 50 is provided around the stacked body 30 when viewed from the stacking direction D1. That is, the frame body 50 is configured to surround the side surface 30 a of the stacked body 30. The frame 50 is provided on the edge 34a of each electrode plate 34, and includes a plurality of first resin portions 52 each having an overhanging portion 52b protruding from the end 34b of the electrode plate 34, and the first resin portion 52 as viewed from the stacking direction D1. And a second resin portion 54 provided around the one resin portion 52.

  The first resin portion 52 constituting the inner wall of the frame 50 is provided from one surface of the electrode plate 34 of each bipolar electrode 32 (here, the surface on which the positive electrode 36 is formed) to the end surface of the electrode plate 34 at the edge portion 34a. It has been. As viewed from the stacking direction D1, each first resin portion 52 is provided over the entire circumference of the edge portion 34a of the electrode plate 34 of each bipolar electrode 32. Adjacent first resin portions 52 are in contact with each other on the surface extending outside the other surface (the surface on which the negative electrode 38 is formed) of the electrode plate 34 of each bipolar electrode 32. As a result, the edge portion 34 a of the electrode plate 34 of each bipolar electrode 32 is buried and held in the first resin portion 52. Similarly to the edge portion 34 a of the electrode plate 34 of each bipolar electrode 32, the edge portions 34 a of the electrode plates 34 disposed at both ends of the laminated body 30 are also held in a state of being buried in the first resin portion 52. Specifically, for the positive electrode-side termination electrode, the first resin portion 52 is also provided on the outer surface (surface connected to the conductive plate 14) of the positive electrode-side termination electrode. That is, the edge portion 34a of the positive electrode-side termination electrode includes a first resin portion 52 (first resin portion 52 provided at the bottom in FIG. 2) provided on the outer surface of the positive electrode-side termination electrode and a positive electrode-side termination. It is held in a state of being buried in the first resin portion 52 provided on one surface of the electrode.

  Between the electrode plates 34 and 34 adjacent to each other in the stacking direction D1, a plurality of internal spaces V that are airtightly partitioned by the electrode plates 34 and 34 and the first resin portion 52 are formed. The internal space V has a first region V1 where an electrolytic solution (not shown) made of an alkaline solution such as an aqueous potassium hydroxide solution is present, and a second region V2 where no electrolytic solution is present. Air is present in the second region V2. The volume of the second region V2 can be, for example, greater than 0 mL and 10 mL or less. The first region V1 and the second region V2 are not partitioned by a member that physically partitions. The atmospheric pressure in the second region V2 is lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. For example, the second region V2 is set to an atmospheric pressure of 50 kPa or less and higher than the saturated vapor pressure of the electrolytic solution.

  In the first resin portion 52 that seals each internal space V as described above, a communication passage 52e (see FIG. 6) communicating with the internal space V is formed. The communication path 52e is formed by omitting or removing a part of the first resin portion 52 (for example, a rectangular parallelepiped region extending in the direction (X direction) intersecting the stacking direction D1). Each internal space V is connected to a pressure regulating valve 60 described later via a communication passage 52e formed in the first resin portion 52 that seals the internal space V.

  The 2nd resin part 54 which comprises the outer wall of the frame 50 is a cylindrical part extended about the lamination direction D1 as an axial direction. The second resin portion 54 extends over the entire length of the stacked body 30 in the stacking direction D1. The second resin portion 54 covers the outer surface of the first resin portion 52 extending in the stacking direction D1. The second resin portion 54 is formed by, for example, injection molding. The 2nd resin part 54 is formed by installing a mold in the peripheral part of the 1st resin part 52, and pouring the resin material of the 2nd resin part 54 which has fluidity in the said mold. Thereby, as shown in FIG. 2, the frame 50 having the first resin portion 52 and the second resin portion 54 is formed.

  The electrode plate 34 is a rectangular metal foil made of nickel, for example. Alternatively, the electrode plate 34 may be a nickel-plated steel plate. The edge portion 34 a of the electrode plate 34 is an uncoated region where the positive electrode active material and the negative electrode active material are not coated, and the uncoated region is buried in the first resin portion 52 constituting the inner wall of the frame body 50. It is an area to be held. An example of the positive electrode active material constituting the positive electrode 36 is nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode 38 include a hydrogen storage alloy. The formation region of the negative electrode 38 on the other surface of the electrode plate 34 is slightly larger than the formation region of the positive electrode 36 on one surface of the electrode plate 34.

  The separator 40 is formed in a sheet shape, for example. Examples of the material forming the separator 40 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), and a woven fabric or a nonwoven fabric made of polypropylene. The separator 40 may be reinforced with a vinylidene fluoride resin compound or the like.

  The frame 50 (the first resin portion 52 and the second resin portion 54) is formed in a rectangular cylindrical shape by, for example, injection molding using an insulating resin. Examples of the resin material constituting the frame 50 include polypropylene (PP), polyphenylene sulfide (PPS), and modified polyphenylene ether (modified PPE).

  One side surface 50s (here, one side surface 50s facing the longitudinal direction (X direction) of the frame body 50) forming one side of the frame body 50 as viewed from the stacking direction D1 includes a plurality (four in this case). An opening 50a is provided. Each opening 50a functions as a liquid injection port for injecting the electrolyte into each internal space V, and also functions as a connection port for the pressure regulating valve 60 after the electrolyte is injected.

  As shown in FIGS. 3 to 6, one opening 50 a is configured by a first opening 52 a provided in the first resin portion 52 and a second opening 54 a provided in the second resin portion 54. Yes. Each first opening 52 a communicates with the internal space V between adjacent bipolar electrodes 32. In each opening 50a, the first resin portion 52 is provided with a plurality (six in this case) of first openings 52a, and the second resin portion 54 has a single opening that covers the plurality of first openings 52a. One second opening 54a is provided. The first opening 52a may be provided in each first resin portion 52, or may be provided between adjacent first resin portions 52. Each of the first openings 52a and the second openings 54a has a rectangular shape, for example.

  In the portion where each opening 50a is provided, the second resin portion 54 is stacked in the stacking direction D1 (Z direction) of the overhang portion 52b of the first resin portion 52 located in the outermost layer (uppermost layer or lowermost layer) of the stacked body 30. A pair of upper and lower extended portions 54b provided on the outer side surface 52c. That is, the extended portion 54 b is formed by a part of the second resin portion 54. Each extended portion 54b has a first side surface 52d constituted by end surfaces of the protruding portions 52b of the plurality of first resin portions 52 and a second side surface 54c continuous in the stacking direction D1. The first side surface 52d and the second side surface 54c are flush with each other.

  In the present embodiment, the nickel metal hydride battery 12 has twenty-four internal spaces V, and one opening 50a has six internal spaces V whose height positions in the stacking direction D1 are shifted by four steps. Communicated with. Each internal space V communicates with any one of the four openings 50a through the communication passage 52e described above. The pressure regulating valve 60 includes a base member 70, a case member 80, a plurality (six in this case) of valve bodies 90, and a cover member 100.

  The base member 70 has a substantially rectangular parallelepiped outer shape, and is formed of, for example, polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), or the like. The base member 70 is connected to the opening 50a. When viewed from the X direction, the lower surface and both side surfaces of the base member 70 are positioned by the second opening 54a. The base member 70 is fixed to the opening 50a by, for example, welding part or all of the contact portions between the side surface 71, the first side surface 52d, and the second side surface 54c. The welding of the side surface 71 with the first side surface 52d and the second side surface 54c is performed by, for example, hot plate welding, laser transmission welding, ultrasonic welding, or the like. The base member 70 is provided with a plurality (six in this case) of first through holes 73 to 78 penetrating from the side surface 71 to the side surface 72. Each of the first through holes 73 to 78 is a communication hole that communicates with the corresponding first opening 52a (communication path 52e).

  The case member 80 is a box-shaped member having a substantially rectangular parallelepiped outer shape, and is formed of, for example, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). The case member 80 is joined to the side surface 72 of the base member 70 at a side surface 81 corresponding to the bottom surface of the box. The case member 80 is provided with a plurality (six in this case) of second communication holes 83 to 88 penetrating from the side surface 81 to the inner side surface 82 (the inner side surface of the side plate forming the side surface 81). The second communication holes 83 to 88 are formed in a columnar shape. Each of the second communication holes 83 to 88 communicates with one internal space V through the corresponding first series of communication holes 73 to 78.

  On the side surface 72 of the base member 70, a partition wall W extending along the connection direction D2 so as to partition each of the plurality of communication paths formed by the plurality of first through holes 73 to 78 when viewed from the connection direction D2. Is formed. A partition wall W extending along the connection direction D2 is formed on the side surface 81 of the case member 80 so as to partition each of the plurality of communication paths formed by the plurality of second communication holes 83 to 88 when viewed from the connection direction D2. Is formed. The base member 70 and the case member 80 are joined to each other by, for example, hot plate welding these partition walls W, W together.

  Inside the case member 80, there is a cylindrical portion 89 that surrounds each of the opening ends 83b to 88b inside the second communication holes 83 to 88 and accommodates a valve body 90 for closing the opening ends 83b to 88b. Is provided. The valve body 90 is formed in a cylindrical shape by an elastic member such as rubber. The valve body 90 extends along the connection direction D <b> 2 while being accommodated in the cylindrical portion 89. The cylindrical portion 89 is formed in a substantially cylindrical shape according to the shape of the valve body 90.

  The valve body 90 accommodated in each cylindrical part 89 is arrange | positioned so that each opening end 83b-88b may be plugged up. Specifically, each of the open ends 83b to 88b has a raised shape raised to the valve body 90 side. By opening the valve body 90 against the respective open ends 83b to 88b having such a raised shape, the open ends 83b to 88b are closed.

  The inner diameter of the cylindrical portion 89 is larger than the diameter of the valve body 90. Further, on the inner side surface of the tubular portion 89, a plurality of protrusions 89 a that abut on the side surface 90 a of the valve body 90 and fix the valve body 90 to the tubular portion 89 are formed. Each protrusion 89a extends along the X direction. Since the side surface 90a of the valve body 90 is supported by the six projecting portions 89a, a gap G corresponding to the size of the projecting portion 89a is formed between the side surface 90a of the valve body 90 and the inner surface of the cylindrical portion 89. Is provided.

  The cover member 100 is a plate-like member joined to the end portion 80b of the case member 80 so as to close the opening 80a of the case member 80. The case member 80 and the cover member 100 are connected to each other so that an accommodation space S in which a plurality of valve bodies 90 are accommodated is formed. The cover member 100 also functions as a pressing member that presses the plurality of valve bodies 90 against the case member 80 along the connection direction D2 so as to press the plurality of valve bodies 90 against the respective open ends 83b to 88b.

  The cover member 100 is made of, for example, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE). A method for joining the cover member 100 to the end portion 80b of the case member 80 is not particularly limited. For example, laser welding, hot plate welding, and fastening using a fastening member such as a bolt can be used. For example, when laser welding is used, the cover member 100 is formed of a laser-transmitting resin, the case member 80 is formed of a laser-absorbing resin, and the laser is irradiated from the cover member 100 side. The boundary part with the cover member 100 can be melted and joined.

  The compression rate of the valve body 90 in a state of being pressed against the case member 80 by the cover member 100 is, for example, the pressure in the second communication holes 83 to 88 (that is, the internal portions communicated with the second communication holes 83 to 88). When the pressure in the space V) falls within a predetermined set value range (for example, 0.5 Mpa or more and 1.2 Mpa or less), the closing of the opening ends 83b to 88b by the valve body 90 is released. It has been adjusted in advance.

  Next, a mechanism for adjusting the pressure in the internal space V will be described. Here, paying attention to the opening end 84b shown in FIG. 6, a mechanism for adjusting the pressure of the corresponding internal space V will be described. The second communication hole 84 communicates with the corresponding internal space V through the first series of holes 74 and the first opening 52a. For this reason, a pressure equivalent to that of the internal space V is applied to a portion that closes the open end 83 b of the valve body 90. As described above, the release of the opening end 84b by the valve body 90 is released when the compression rate of the valve body 90 is such that the pressure in the corresponding internal space V becomes equal to or higher than a predetermined set value. It is prescribed. For this reason, when the pressure in the corresponding internal space V is less than the set value, the closed state in which the opening end 84b is closed by the valve body 90 is maintained as shown in FIG.

  On the other hand, when the pressure in the internal space V increases and becomes equal to or higher than the set value, a part of the valve body 90 (specifically, a portion that closes the opening end 84b and its peripheral portion) is removed from the opening end 84b. The valve is deformed so as to be separated from the opening end 84b, and the open end state is released. As a result, the gas in the internal space V is released from the open end 84b where the blockage is released. After that, when the pressure in the internal space V becomes less than the set value, the valve body 90 returns to the original state, so that the open end 84b is closed again (the state shown in FIG. 6). . With the above opening / closing operation, the pressure adjusting valve 60 can appropriately adjust the pressure in the internal space V. The mechanism for adjusting the pressure in the internal space V corresponding to the other open ends 83b, 85b to 88b is the same as the mechanism described above.

  Further, an exhaust port 100a (two exhaust ports 100a in the example of FIG. 4) that connects the housing space S and the external space is provided at a position that does not overlap with the plurality of valve bodies 90 when viewed from the connection direction D2. It has been. Accordingly, the gas released from the internal space V through the first communication holes 73 to 78 and the second communication holes 83 to 88 is appropriately stored in the external space through the exhaust port 100a without accumulating in the accommodation space S. Can be discharged.

  In the nickel metal hydride battery 12 of the above embodiment, the atmospheric pressure of the second region (residual space where no electrolytic solution is present) V2 in the internal space V is lower than the atmospheric pressure and lower than the saturated vapor pressure of the electrolytic solution. high. For this reason, the pressure rise becomes gentle when the second region V2 is filled with gas. In other words, when the second region V2 is in an atmospheric pressure state, when the pressure is lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution, a larger amount of gas is accepted before reaching a certain pressure. Can do. As a result, even if a large amount of gas is generated instantaneously, the time until the pressure regulating valve 60 acts increases, so that the output of the nickel metal hydride battery 12 can be increased.

  In the nickel-metal hydride battery 12 of the above embodiment, the pressure rise when the second region V2 is filled with gas becomes moderate, and accordingly, the volume of the second region V2 can be reduced. That is, the second area V2 as the buffer area until the predetermined atmospheric pressure is reached can be reduced. Thereby, the physique of the nickel metal hydride battery 12 in a plan view viewed from the Z direction (first direction) can be reduced.

  In the nickel metal hydride battery 12 of the above-described embodiment, since the atmospheric pressure in the second region V2 is 50 kPa or less, it is possible to increase the output of the nickel metal hydride battery 12 more reliably and more efficiently.

  Since the internal space V of the nickel-metal hydride battery 12 of the above embodiment is a very narrow space in which the volume of the second region V2 is greater than 0 mL and 10 mL or less, the pressure is likely to increase. Even with such a configuration, it is possible to increase the output of the nickel-metal hydride battery by setting the atmospheric pressure in the second region V2 to be lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution.

  In the power storage device 10 of the above-described embodiment, the opening direction of the second communication hole 84 forming the pressure regulating valve 60, the first communication hole 74 communicating with the second communication hole 84, and the first opening 52a is horizontal. In many cases, the nickel-metal hydride battery 12 is arranged so as to face. In such a case, when the valve body 90 of the pressure regulating valve 60 is opened, there is a high possibility that the electrolyte leaks from the internal space V. In the nickel metal hydride battery 12 of the above embodiment, the valve body 90 is difficult to open by setting the atmospheric pressure in the second region V2 to be lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. For this reason, even if it arrange | positions so that the opening direction of the 2nd communicating hole 84, the 1st continuous hole 74, and the 1st opening 52a of the nickel hydride battery 12 may face a horizontal direction, the leakage of electrolyte solution can be suppressed.

  Next, in the configuration of the nickel-metal hydride battery 12 having the above-described configuration, a method (storage module) in which the atmospheric pressure in the second region V2 of the internal space V is lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. An example of the manufacturing method) will be described. As shown in FIG. 7, the manufacturing method of the nickel metal hydride battery 12 of the present embodiment includes a preparation step S1, a welding step S2, an electrolyte injection step S3, and a regulating valve connection step S4.

  In the preparation step S1, a bipolar electrode 32 composed of an electrode plate 34 having a positive electrode 36 formed on one surface and a negative electrode 38 formed on the other surface, and a frame-shaped first resin portion 52 are prepared. In the welding step S <b> 2, the frame-shaped first resin portion 52 prepared in the preparation step S <b> 1 is placed on the peripheral portion of the electrode plate 34, and the first resin portion 52 is welded to the peripheral portion of the electrode plate 34. The first resin portion 52 is welded to the electrode plate 34 by, for example, hot plate welding, laser transmission welding, ultrasonic welding, or the like.

  In the electrolytic solution injection step S3, the units manufactured in the welding step S2 and having the first resin portion 52 welded to the electrode plate 34 are stacked, and the units are welded to each other. Also in this welding, adjacent units are welded to each other by, for example, hot plate welding, laser transmission welding, ultrasonic welding, or the like. In the electrolyte injection step S3, in the laminate 30 formed by being laminated in this manner, the inner space V formed by being surrounded by the electrode plates 34 and 34 and the first resin portion 52 adjacent to each other is electrolyzed. This is a step of injecting a liquid. In the electrolytic solution injection step S3, the atmospheric pressure in the internal space V is made lower than that in the external space outside the first resin portion 52, and the electrolytic solution is injected due to the atmospheric pressure difference between the internal space V and the external space. In the electrolytic solution injection step S3, the amount of the injected electrolytic solution is adjusted so that a region (second region V2) where the electrolytic solution does not exist is formed in the internal space V.

  In the regulating valve connection step S4, the pressure regulating valve 60 is connected to the opening 50a of the stacked body 30 into which the electrolytic solution has been injected in an environment that is lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. Specifically, the laminate 30 into which the electrolyte solution has been injected in the electrolyte solution injection step S3 is stored in a storage unit provided in a pressure adjusting device capable of adjusting the atmospheric pressure. In the regulating valve connection step S4, the atmospheric pressure in the accommodating portion is set to 50 kPa or lower and higher than the saturated vapor pressure of the electrolytic solution. In addition, in the regulating valve connection step S4, the amount of the electrolyte to be injected is adjusted so that the volume of the region where the electrolyte does not exist in the internal space V (that is, the second region V2) is greater than 0 mL and equal to or less than 10 mL. . In addition, the atmospheric pressure (that is, the atmospheric pressure in the second region V2) in the housing portion is appropriately set based on the characteristics and amount of the electrolyte, the volume of the second region V2, and the like. The pressure regulating valve 60 is connected by a hot plate welder under the above environment. Thereby, the atmospheric pressure in the second region V2 of the internal space V that has become atmospheric pressure when the electrolytic solution is injected in the electrolytic solution injection step S3 can be reduced once again. In the present embodiment, the atmospheric pressure in the second region V2 of the internal space V can be set to 50 kPa or lower and higher than the atmospheric pressure at which the electrolytic solution boils.

  In the manufacturing method of the nickel metal hydride battery 12 of the above embodiment, the pressure regulating valve 60 is provided in the opening 50a of the laminate 30 into which the electrolytic solution has been injected in an environment lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution. Since it connects, the pressure of the internal space V after connecting the pressure control valve 60 can be made lower than atmospheric pressure and higher than the saturated vapor pressure of electrolyte solution. For this reason, the pressure rise becomes gentle when the second region V2 is filled with gas. In other words, when the second region V2 is in an atmospheric pressure state, when the pressure is lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution, a larger amount of gas is accepted before reaching a certain pressure. Can do. As a result, even if a large amount of gas is generated instantaneously, the time until the pressure regulating valve 60 acts increases, so that the output of the nickel metal hydride battery 12 can be increased.

  As mentioned above, although one embodiment was described in detail, the present invention is not limited to the above-mentioned embodiment.

  In the above-described embodiment, all the atmospheric pressures in the internal space V that is hermetically partitioned by the electrode plates 34 and 34 adjacent to each other in the stacking direction D1 and the first resin portion 52 are lower than the atmospheric pressure, and the saturated vapor of the electrolytic solution. Although an example configured to be higher than the pressure has been described, the present invention is not limited to this. For example, the air pressure in some of the internal spaces V may be configured to be lower than the atmospheric pressure and higher than the saturated vapor pressure of the electrolytic solution.

  In the above embodiment and the modification, as illustrated in FIG. 4, the pressure regulating valve 60 provided with the valve body 90 in each of the communication holes communicating with the internal space V has been described as an example, but the internal space V is predetermined. As long as the pressure in the internal space V is released when the pressure becomes equal to or higher than the pressure, any pressure regulating valve may be used. Moreover, although the pressure regulating valve 60 of the above embodiment has been described by taking as an example a configuration that closes again when the pressure in the internal space V is released, a configuration (pressure) that does not return to the closed state while the valve is open Release valve).

  In the said embodiment and modification, although the electrode plates 34 and 34 adjacent to the lamination direction D1 and the internal space V partitioned off airtightly by the 1st resin part 52 were mentioned and demonstrated, the example was formed, The internal space may be formed by a container that houses the laminate. Moreover, the number of internal spaces may be one.

  In the said embodiment and modification, although the example which forms the frame 50 by welding the 1st resin part 52 to the peripheral part of the electrode plate 34 was given and demonstrated, the frame was formed in the peripheral part of the electrode plate 34 by injection molding. The body 50 may be formed.

  Moreover, although the said embodiment and modification demonstrated and demonstrated the manufacturing method of the nickel hydride battery, you may apply to the manufacturing method of a lithium ion secondary battery. In this case, a configuration including a laminate in which an electrode plate on which a positive electrode is formed and an electrode plate on which a negative electrode is formed is laminated via a separator may be employed. The positive electrode active material is, for example, a composite oxide, metallic lithium, sulfur or the like. Examples of the negative electrode active material include carbon such as graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, and SiOx (0.5 ≦ x ≦ 1.5). And metal oxides such as boron and carbon added with boron. For the electrode plate, stainless steel foil or the like can be used.

  DESCRIPTION OF SYMBOLS 10 ... Power storage device, 12 ... Nickel metal hydride battery, 30 ... Laminated body, 32 ... Bipolar electrode, 34 ... Electrode plate, 36 ... Positive electrode, 38 ... Negative electrode, 40 ... Separator, 50 ... Frame (container), 52 ... First One resin part, 54 ... second resin part, 60 ... pressure regulating valve, D1 ... stacking direction, D2 ... connection direction, S1 ... preparation step, S2 ... welding step, S3 ... electrolyte injection step, S4 ... regulating valve connecting step , V ... internal space, V1 ... first region, V2 ... second region.

Claims (10)

A nickel-metal hydride battery having a laminate in which a bipolar electrode composed of an electrode plate having a positive electrode formed on one surface and a negative electrode formed on the other surface is laminated in a first direction through a separator,
A container for housing the laminate;
A pressure regulating valve connected to an opening communicating with the internal space surrounded by the container,
The internal space has a first region where an electrolyte containing potassium hydroxide is present and a second region where the electrolyte is not present,
The nickel-metal hydride battery, wherein the pressure in the second region is lower than atmospheric pressure and higher than the saturated vapor pressure of the electrolyte.   The nickel metal hydride battery according to claim 1, wherein the volume of the second region is greater than 0 mL and equal to or less than 10 mL.   The nickel hydrogen battery according to claim 1 or 2, wherein the pressure regulating valve opens in a range where the pressure in the internal space is 0.5 MPa or more and 1.2 MPa or less.   The nickel metal hydride battery according to any one of claims 1 to 3, wherein the air pressure in the second region is 50 kPa or less. The container is a frame that holds a peripheral edge of the electrode plate and covers a side surface orthogonal to the first direction in the laminate.
5. The nickel hydrogen battery according to claim 1, wherein the pressure regulating valve is connected to an opening communicating with each of a plurality of internal spaces surrounded by the electrode and the frame adjacent to each other. A laminated body in which an electrode made of an electrode plate on which at least one of a positive electrode and a negative electrode is formed is laminated in a first direction via a separator, a housing body that houses the laminated body, and an internal space surrounded by the housing body A pressure regulating valve connected to an opening that communicates, and a method of manufacturing a power storage module comprising:
An electrolyte injection step of lowering the atmospheric pressure of the internal space below the atmospheric pressure of the external space of the container, and injecting an electrolytic solution into the internal space by a pressure difference between the internal space and the external space;
A regulating valve connecting step of connecting the pressure regulating valve to the opening of the internal space into which the electrolytic solution has been injected, and
In the electrolyte injection step, the amount of the electrolyte to be injected is adjusted so that a region where the electrolyte does not exist is formed in the internal space.
In the method for manufacturing a power storage module, the regulating valve connection step includes connecting the pressure regulating valve to the opening in an atmospheric pressure environment lower than atmospheric pressure and higher than a saturated vapor pressure of the electrolytic solution. The electrode is a bipolar electrode in which a positive electrode is formed on one surface of the electrode plate and a negative electrode is formed on the other surface;
The power storage module is a nickel metal hydride battery,
The method for manufacturing a power storage module according to claim 6, wherein the electrolytic solution contains potassium hydroxide. The container is a frame that holds a peripheral edge of the electrode plate and covers a side surface orthogonal to the first direction in the laminate.
8. The power storage module according to claim 6, wherein in the adjustment valve connection step, the pressure adjustment valve is connected to an opening communicating with each of a plurality of internal spaces surrounded by the electrodes and the frame adjacent to each other. Production method.   The power storage module according to any one of claims 6 to 8, wherein, in the regulating valve connection step, the pressure regulating valve is connected to the opening in a pressure environment of 50 kPa or less and higher than a saturated vapor pressure of the electrolyte. Manufacturing method.   The said adjustment valve connection process WHEREIN: The quantity of the said electrolyte solution to inject | pour is adjusted so that the volume of the area | region where the said electrolyte solution does not exist in the said internal space may be larger than 0 mL and 10 mL or less. A method for manufacturing the electricity storage module according to claim 1.

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